US2250012A - Web guide - Google Patents

Description

WEB GUIDE Filed July 13, 1939 FIG.1

INVENTOR. WILLIAM H. EDDY ATTORNFTV Patented July 22, 1941 2,2 o,o1z

' was GUIDE William n. Eddy, Downers Grove, 1u., a'ssignor to Teletype Corporation, Chicago, 111., a corporation of Delaware Application July 13, 1939, Serial No. 284,259-

3 Claims.

The present invention relates to apparatus for feeding page width webs of printing material and particularly to mechanism intended for use with line feed shiftable-printing platens or carriages of printing telegraph machines.

Apparatus for printing transversely on wide webs sometimes employ stationary printing mechanism comprised of levers arranged in a semi-circular grouping in combination with longitudinally shiftable printing platens. The platen is usually supported in a carriage or frame and the entire assembly is advanced step by step for printing of each character. Following the completion of a line, the carriage is returned in a single movement to a starting position. These transverse movements of the platen and carriage induce a corresponding movement on the part of the paper web which is tensioned against the platen to resist transverse displacement. In order to prevent torsional displacement of the web during the course of movement of the platen and carriage, a web supply roll holder may be supported upon a mandrel or other suitable pivot which is integrally associated with the carriage so as to be moved in unison therewith.

Under certain conditions, however, the outlined procedure is not practical for the reason that paper web supply rolls of exceedingly large dimensions and correspondingly large mass are frequently used for the purpose of affording a larger reserve capacity and to avoid frequent replenishment. The additional mass which is added by the weight of the moving web supply roll appreciably affects the return speed of the platen carriage, particularly in the case of automatic printing machines, such as telegraphically operated printers. cially in the case of the automatic carriage return function or operation. Accordingly, while it is highly desirable to utilize a large supply roll. and this practice is even more attractive in the case of multiple copy for carbon interleaved webs, the added mass of the supply roll so affects the response to the carriage return signal of printing telegraph apparatus that the results are unsatisfactory, frequently causing a condition where printing takes place during transit of the carriage.

A principal object of the present invention consists in the provision of a compact paper supply fixture capable of supporting relatively large or massive rolls of paper in close proximity to a housing which confines a shiftable carriage printing machine.

A retardation is noted, espe- In order to use massive supply rolls of paper web while at the same time permitting the normal instantaneous response of the carriage to its return signal, an apparatus is proposed herewith which will permit of the use of a stationary supporting fixture for carrying the supply roll so that its weight is not a contributory mass to interfere with the movement of the carriage, while' still the paper web may be afforded ample freedom to move with and respond to the influences of the longitudinally shiftable carriage, both during the course of step-by-step movement in printing operation as well as during the course of instantaneous return movement in response to the carriage return signal.

Towards this end a device is provided intermediate a stationary supply roll supporting fixture and a printer housing which contains a shiftable carriage printing apparatus, which intermediate device operates as an equalizer and aligner for distributing the torsional stresses throughout the width of the web so that the pull exerted by the rotating paper platen is applied equally throughout the full width of the web, and also to guide the paper into the platen perpendicularly. In the performance of this purpose, the equalizer and aligner device occupies but little space intervening the supply roll and the printer housing, accordingly permitting of a compact relationship between the printer hous ing machine and the paper supporting fixture.

For a more comprehensive understanding of the instant invention, reference will now be had to the accompanying drawing and to the detailed description following hereinafter in which similar reference characters designate corresponding parts throughout and in which,

Fig. 1 is a perspective view partly broken away observing from the rear a typical telegraph printing apparatus having applied thereto equipment paper rolls II and angling sidewardly as at 15 to i double back as at It and be secured to the rear wall ll of a printer housing unit.

Within the space which is afforded transversely between the frame members It and IS on both the right and left portions of the supporting frame assembly there extends a trapezoidal framework It. Member I8 is an integrally fabricated device formedfof round stock and flattened as at l9, whereat is secured the pivot ear 2|. At the Junction of the pivot ear 2| and flattened portion Isis also located a pivotal opening through which passes a pivot screw or rivet 1 22, the latter extending from a supporting bracket 23 fast to the printer housing. Another and somewhat larger opening 24 situated in the upwardly extending section of said ear 2| is large enough to admit the motion limiting projection solidand dotted outline, Fig. 2. Paralleling the bottom rod 23 of the trapezoidal member I3 is an intermediate rod 21 over whiclr is threadedthe several web sheets which comprise the collective web 32 as it leaves the roll proper and'following which the same web, now indicated 33, is threaded under said bottom rod 23, Fig. 1.

After passing under the rod 23, the web, now indicated 3|, continues upwardly in the original direction again entering the printer unit housing through the elongated slot 23. It is to be noted that slot 28 is of sufllcient width to accommodate the lateral movement of the web throughout its extremities of movement; that is, from one side to the other. Upon entering the enclosure of the printer housing, the web is received over suitable guides and tensioned around a cylindrical printing platen against the peripheral surface of which it is held by means of pressure rollers (not shown). The printing platen 20 is carried on a shaft 30, maintained in parallel relationship with the shaft l2 of the supply roller, and mechanism (not shown) is provided to reciprocate the platen 20 along its axis of rotation during the operation of the printer.

The particular arrangement for pulling or feeding the web is immaterial to the present invention except to note that during the course of printing it is contemplated that the web is to be shifted transversely in one direction throughout successive steps following the printing of each character or the execution of each character space function. The movement of the web transversely in the. opposite direction is executed in one motion under the selective control of mechanism responsive to a carriage returnsignal. Accordingly, it is to-be understood that except during the period of central alignment, substantially as shown in Fig. 1, the web undergoes to some extent unequal longitudinal and torsional stresses.

It will now. be explained how the trapezoidal member ID functions to distribute the aforementioned unequal stresses so that the pull which is exerted longitudinally upon the web, will not be concentrated upon either end of the web transversely speaking, but will instead be made to pivot member i8 and through it to effect a more equal distribution of the longitudinal stresses throughout the transverse width of the web. Also, it will be shown how by means of the trapezoidal member I8, an adjustment is made intermediate the length of the web, that is to say, between the point at which it leaves the tape supply roll and the point at which it enters the unit and is received by the printing platen, whereby parallelism is maintained notwithstanding the side-to-side movement of the platen and the relatively stationary supply roll.

It should be observed that the rotational axes of the supply roller l2 and of the platen (not illustrated) are at all times parallel, but that in accordance with the contemplated mode of operation the two members are not at all times in alignment longitudinally. Under conditions of extreme displacement, that is when the printing platen is at either of its extremities of motion, the maximum out-of-line transverse condition is attained. Under such circumstances an extreme torsional stress is set up in the web attempting to bring the ingress terminal 3| of the web into transverse alignment with the supply roll. As a result, the paper attempts to buckle and the interleaved sheets of carbon having a smaller friction resistance to overcome are accordingly influenced by said torsional stresses as the web is advancedlongitudinally until they become displaced with respect to their adjacent sheets of paper web. As the platen is shifted into the other direction an opposite torsional stress is set up and the carbon sheets attempt to adjust themselves in an opposite manner but, as experiment has proved, a condition is attained under which the carbon paper escapes beyond tant to note that not only are the web sections 3| and 32 maintained parallel but that in so maintaining them there is preserved the perpendicular alignment with the printing platen. As a result, the several sheets of paper and carbon are held in stack alignment, thereby preventing the creeping action which it otherwise experienced. Theintermediate portion of the web ln-' dicated 33, Fig. 2, takes the shape of a parallelogram at all times varying in proportion only in accordance with the angular position of the trapezoid I8. Accordingly, the edges of the web are then maintained at equal length, as may be observed from Fig. 2, and calculated geometrically and the pull exerted by the printing platen and its tensioning roller maintained at all times equal throughout the transverse width of the web.

While the present invention has been described in contemplation of a specific embodiment, it is to be understood, nevertheless, that numerous changes and modifications may be made without departing from the spirit or scope thereof. Accordingly, it is not intended to be limited by the specific language of the foregoing description nor by the particular details in the accompanying drawing except as indicated in the hereunto appended claims.

What is claimed is:

1. In an arrangement for feeding a web, a supply roll, a feed roll maintained in constant parallel axis relationship with said supply roll, one of said rolls being movable along an axis parallel to the axis of the other of said rolls, and means to maintain a longitudinal adjustment in a web be tween said feed and supply rolls comprising a trapezoidal frame member having a first rod over which the web is threaded from said supply roll, a second rod under which the web is threaded after leaving said first rod and beyond which it is pulled by said feed roll, and means located above said rods for pivotally supporting said trapezoidal member on an axis substantially transverse to said parallel axes of said supply and feed rolls.

2. In a printing telegraph apparatus, a printing platen consisting of a cylinder maintained upon a horizontal axis of rotation and shiftable longitudinally along its said axis coincidentally with character printing and carriage return functions, a supply roll rotatably supporting a stock of paper web along a horizontal axis parallel to the axis of said platen, and means for adjusting said web intermediate said supply roll and said platen to compensate for out-of-line conditions therebetween resulting from said longitudinal shitting comprising a frame having a pair of parallel different length rods over one and under the other of which said web is threaded intermediate said platen and supply roll, and means above the shorter of said rods for pivoting said frame whereby said frame may be moved in accordance with alignment variations between said supply roll and said platen.

3. A printing telegraph apparatus including a printer housing, a paper web feed platen having a horizontal axis of rotation and shiftable longitudinally on its axis in said housing, a paper supply supporting mandrel having a horizontal axis of rotation for supporting a roll of paperin an axially stationary position outside said housing, and means for displacing the paper web from a line corresponding to its direction of leaving the paper supply roll to a line corresponding to its direction of pull by said platen comprising a pendulously supported frame apparatus, pivot means for so supporting said frame apparatus, an

upper guide rod in said apparatus over which said paper web is fed from said roll, a lower guide rod on said apparatus parallel to said upper rod and under which said paper web is fed after leaving said upper guide rod and following which it is directed to said printing platen, said lower guide rod being more remote from the pivot by which said frame is supported than said upper guide rod whereby said lower guide rod is made to describe a greater radius or travel than the upper rod.

WILLIAM H. EDDY.

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